I have no idea what this is. A movie or a live action TV series or maybe just a music video. Either way I think it's not really gonna be all that good. A BIG part of what made the K-ON! anime so good was the cast of Seiyu that do all the singing for the show and anything live action would more then likely not involve them as they more then likely don't look like the characters they play. So without them it loses one of the biggest draws K-ON! has. It's music.

I tend to think whatever this is it's just Dannychoo messing with people. If it was something important like a TV series or movie ANN would have long since known about it and reported on it because it would be a big deal and choo messes with people quite often with completely pointless stuff.

Indeed. If this was a movie or TV series, I think we would've heard about it before now. I don't recognise any of those girls as J-pop singers, so I'm thinking at best it's some short doujin K-on thing.